texture is facing the wrong side of the mesh
It seems to me the texture is facing the camera... 



One issue I did find is that you are mixing a transparent shader using an alpha channel, but your image has no such thing (jpeg images do not support alpha chanels), so that section of your node setup has no effect. 



The backside of the petal is indeed colorless, but that is the effect of the hue saturation node affecting the traslucency (as @gandalf3 pointed out).



If you want to change the texture to the back of the object, add a Geometry node and use the backfacing information to control on which side the texture gets mapped...



EDIT 
(given that the question is so vague, the shared file linked to the different images, and the project layout open to so much interpretation...)

Is the error maybe that the UV mapping is upside down?

In the UV/Image_Editor window you can select the UV mapping and rotate it manually using the R key.



To rotate 180 degrees press R180

To flip the UV mapping press S-
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